Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Sieries of Clunks when Accelerating? *SOLVED*

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by SAVAGE1, Mar 22, 2002.

  1. SAVAGE1

    SAVAGE1 1/2 ton status

    Joined:
    May 22, 2000
    Posts:
    1,104
    Likes Received:
    0
    Location:
    BAY AREA, CA
    I recentlly developed a strange noise while accelerating from a dead stop. I get a sieres of 1-5 clunks when accelerating normally. And for some reason it tends to do it more when I'm making a left. It doesn't do it everytime but its enough to worry me. I feel the popping right under my feet.

    I've checked the following with no luck: engine/ tranny mounts, body mounts, frame around steering box, retorqued Ubolts, crossmember bolts, adapter bolts, bellhousing bolts, converter bolts, checked driveshaft Ujoints, front axle Ujoints look fine and that's about it.
    I jacked up the rear tires and inspected everything in motion. The Tcase seemed to have a lot of play in the interals. Nothing too abnormal though. At cruising speeds I don't get the sound at all, only during accelration. Did I miss anything? Thanks in advance.
     
  2. TopOff

    TopOff 1/2 ton status

    Joined:
    Jan 16, 2002
    Posts:
    1,760
    Likes Received:
    0
    Location:
    Folsom, ca
    Re: Sieries of Clunks when Accelerating?

    Check U-bolt torque. My front left seems to come loose more than the others. It clunks only after I accelrate from a turn. In other words, I turn the wheel all the way to the right then accelerate, then I get a clunk or two. That is when I know my U-bolts are loose.

    Other issue could be the u-joints are too tight!

    Good luck.
     
  3. HarryH3

    HarryH3 1 ton status Author

    Joined:
    May 31, 2000
    Posts:
    10,384
    Likes Received:
    2
    Location:
    Georgetown, TX
    Re: Sieries of Clunks when Accelerating?

    Also take a look at the front spring shackles. The left one is right under the drivers feet. A bad bushing can make some strange noises under there.
     
  4. SAVAGE1

    SAVAGE1 1/2 ton status

    Joined:
    May 22, 2000
    Posts:
    1,104
    Likes Received:
    0
    Location:
    BAY AREA, CA
    Re: Sieries of Clunks when Accelerating?

    I already checked the Ubolts. And my front shackle bushing is new so I don't think its that. Thanks, keep 'em coming.

    Can a Ujoint really be too tight? Also, I had my brother shift in and out of gear while I was under the truck and I heard a clunk coming from around the Tcase. As I mentioned above the Tcase had some play. Does this sound like a Tcase going bad? Its a 208.
     
  5. DesertDueler

    DesertDueler 1/2 ton status

    Joined:
    May 23, 2001
    Posts:
    3,106
    Likes Received:
    0
    Location:
    Phoenix, AZ
    Re: Sieries of Clunks when Accelerating?

    All the 208s I have had or have seen have alot of play in it. That noise is common. Did you check for excesive play in the rear end? Also do you have a Gov Lock, because if you do it sounds like its getting ready to blow up /forums/images/icons/smile.gif
     
  6. sarazk5

    sarazk5 1/2 ton status

    Joined:
    Feb 19, 2001
    Posts:
    713
    Likes Received:
    0
    Location:
    Sacramento, CA
    Re: Sieries of Clunks when Accelerating?

    I get these noises also. Something has been causing a bad vibration. My crossmember bolts under my tranny keep comming loose. In fact popped off the other day. Today on way to work all of a sudden I had a ton of vibration... and that clunking again. i think i blew another Ujoint. But like the other guy said... if you have a gov. lock it makes those same clunks. Mine blew a couple of weeks ago. It sounded like it was popping under my feet. It ended up shooting a hole through my diff cover. Fortunately we were able to break the rest of it out and remove it... for now I have an open diff.
    Sorry if this didn't help... just sharing similar problems.

    Sara
     
  7. SAVAGE1

    SAVAGE1 1/2 ton status

    Joined:
    May 22, 2000
    Posts:
    1,104
    Likes Received:
    0
    Location:
    BAY AREA, CA
    Re: Sieries of Clunks when Accelerating?

    I blew my 10 bolt GovLoc last year. I have a 14B FF (open) under it now so that's ruled out. Basically I replaced my entire drivetrain from engine to axles except for the Tcase. That's why I suspect it to be the problem. I have a new 1Ton driveshaft and everythings tight. I'm running out of places to look and this is annoying me.

    Here's a little background on the rig: I dropped my Tcase to help with the vibes and I never had the sound. Recently I put in a new engine and tranny and when I got everything back together I left the Tcase in the "up" (stock) position. After a week of driving the truck, I droped the Tcase back down and that's when I noticed the sound. I don't know if that has anything to do with it but hopefully someone has the answer. Thanks for your reply's.
     
  8. gokartergo

    gokartergo 3/4 ton status Staff Member Moderator

    Joined:
    Dec 2, 2000
    Posts:
    5,855
    Likes Received:
    0
    Location:
    Hollister, CA
    Re: Sieries of Clunks when Accelerating?

    Have you checked your exhaust Y pipe hitting the front drive line or did you already extend that...Dan
     
  9. SAVAGE1

    SAVAGE1 1/2 ton status

    Joined:
    May 22, 2000
    Posts:
    1,104
    Likes Received:
    0
    Location:
    BAY AREA, CA
    Re: Sieries of Clunks when Accelerating?

    I had the Y pipe extended already, plus my front driveshaft isn't installed right now. This is really starting to bug me. I'm just about done breaking in the new engine but I'm scared to really get on the pedal with that noise there. I feel the clunk when the tranny downshifts also, like there's something loose in the drivetrain. This sucks, I'm gonna go through every bolt tomorrow.
     
  10. dano_nd

    dano_nd Newbie

    Joined:
    Mar 24, 2002
    Posts:
    1
    Likes Received:
    0
    Re: Sieries of Clunks when Accelerating?

    Rod - my '90 Suburban does the EXACT same thing. The 3-2 downshift gives a "clunk" and I get the same "clunk" when I accelerate from a stop. I do know my rear-end is pretty shot, so I'm assuming it's something to do with that. Let me know if you figure out exactly what it is!
     
  11. SAVAGE1

    SAVAGE1 1/2 ton status

    Joined:
    May 22, 2000
    Posts:
    1,104
    Likes Received:
    0
    Location:
    BAY AREA, CA
    I GOT RID OF THE CLUNK! As I was saying above, the noise developed after I dropped my Tcase. So over the weekend I put it back up to stock and the noise dissapeared. What confuses me is that I had the Tcase dropped before my engine swap and I had no clunk. I guess the rear slip yoke was binding somehow because of the angle. I just can't figure it out. Well no use thinkin bout it any more. Just gotta deal with my driveshaft vibe.
     
  12. gokartergo

    gokartergo 3/4 ton status Staff Member Moderator

    Joined:
    Dec 2, 2000
    Posts:
    5,855
    Likes Received:
    0
    Location:
    Hollister, CA
    When you dropped the t-case to check and see if your dist. was hitting the firewall....Dan
     
  13. SAVAGE1

    SAVAGE1 1/2 ton status

    Joined:
    May 22, 2000
    Posts:
    1,104
    Likes Received:
    0
    Location:
    BAY AREA, CA
    Yeah the dist. was not touching the firewall. Had to be the Tcase binding somehow.
     
  14. gokartergo

    gokartergo 3/4 ton status Staff Member Moderator

    Joined:
    Dec 2, 2000
    Posts:
    5,855
    Likes Received:
    0
    Location:
    Hollister, CA
    That's a wierd one... Usually dropping the t-case helps the angle..Dan
     
  15. Zeus33rd

    Zeus33rd Smarter than you GMOTM Winner

    Joined:
    Mar 14, 2002
    Posts:
    7,324
    Likes Received:
    9
    Location:
    Grass Valley, CA
    Hmm......Something doesnt make sense....You've checked the condition of the transfer case-to-crossmember mount right? Budz '90K5 with 700R4, had a mount with pretty much no rubber left in it...Did the same thing...clunking when accellerating. A new mount solved the prob.
     
  16. SAVAGE1

    SAVAGE1 1/2 ton status

    Joined:
    May 22, 2000
    Posts:
    1,104
    Likes Received:
    0
    Location:
    BAY AREA, CA
    Yeah I was thinkin the mount, but everyone seems to be out of stock (poly urathane mounts). When I replace it I'll try to drop the case again.
     
  17. 84_Chevy_K10

    84_Chevy_K10 Banned

    Joined:
    May 30, 2001
    Posts:
    17,669
    Likes Received:
    0
    Location:
    IL, USA
    Poly there might cause vibrations to be transmitted to the body anyway. Get a new rubber one at Autozone for $18 with a lifetime warrenty. If you ever have the tranny out, take it back and get a new one. They're good about taking stuff back.
     
  18. Zeus33rd

    Zeus33rd Smarter than you GMOTM Winner

    Joined:
    Mar 14, 2002
    Posts:
    7,324
    Likes Received:
    9
    Location:
    Grass Valley, CA
    You beat me to it 84...Was gonna say the same thing. /forums/images/icons/smile.gif
     
  19. SAVAGE1

    SAVAGE1 1/2 ton status

    Joined:
    May 22, 2000
    Posts:
    1,104
    Likes Received:
    0
    Location:
    BAY AREA, CA
    Thanks, I'll give it a try.
     

Share This Page